Pipes - Work Distance Concept - Arithmetic, Quantitative Reasoning Video Lecture | Quantitative Aptitude (Quant) - CAT

so let us take one more problem which is
pipes question or the concept of pipes
which is related to the time and work
units concept so let us begin with a
simple situation a pipe a can fill that
tank in six hours pi b can fill the same
tank in 10 hours while pipe see can
remove the water or drain the water in
15 hours so all the three pipes are open
together the tank is completely empty to
begin with in how many hours will the
tank be full so again apply the concept
of units take the total units as the LCM
of 6 10 and 15 so let's say 30 units so
in 30.if 30 is a total unit pipe a can
fill how many units per hour we will get
5 units per hour this is plus 5 pi b can
fill in plus 3 units per hour while pipe
see can remove minus 2 units per hour so
in other words the net is plus 5 plus 3
minus 2 which will give us six units per
hour and we have to go till 30 units and
therefore the answer will become exactly
five hours so in five hours that time
will be full so this is a concept of
pipes basically it is nothing but same
as the units can say which we applied in
time work there is a small thing which
is five C which is drainage pipe so we
are actually doing work destroyer
concept but what we need to understand
we have to put in minus sign in that
minus sign lagana whopper Jabie drainage
yeah leakage voila situation is to let
us take one problem which has come in
the cat exam as well pipe a can fill
that tank in 12 minutes pi b can fill
the same tank in 12 in 10 minutes i am
sorry a in 12 minutes be in 10 minutes
while pipe see can remove the water at
the rate of twenty four liters per
minute initially the tank is full all
the three pipes are open together
and in exact one hour the temp gets
empty the question is what is the volume
or what is the capacity of the tank so I
am sure there can be various methods of
solving equation method as well but I
would like to tell you one very very
good shortcut trick in one hour if you
look at pipe a it will fill how many
times the tank it will fill five times
pi be a condemning kitten e barbarita by
the same logic by beaver riga Chebar
Chuck use cover and M&A this minute to
do know me lekar kitnik and delivering a
do know Malaka a containment kidney
barbering a and B the dough know Malaka
birthing game 11 times 5 plus 6 11 times
or egg barbell ever aware and therefore
the total 12 times the tank will be
filled in one hour now look at pipe c5c
is taking out 24 litre per minute so in
exact one hour how many liters the water
will go out so it will go out as 24 into
60 so in other words we can now write 12
into V where V is the volume 12 into V
is equal to 24 into 60 whatever the
number of liters coming out in the
system should be going out from the
system because finally the tank is empty
so solving for V we get 24 into 60 / 12
and the answer is 120 liters